Introduction To ANS Flashcards by ibukun ruth

The nervous system is made up of❓

Central NS:
Brain
Spinal cord
Peripheral NS:
Somatic NS

Autonomic NS:
Sympathetic(thoracolumbar)
Parasympathetic(craniosacral)

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What is the basic anatomical difference btwn the motor pathway of the somatic ND and the autonomic NS❓

Somatic NS:
Cell bodies of motor neurons reside in the CNS and their axons extend to skeletal muscles

Autonomic NS:
usually 2 neurons
preganglionic neuron in CNS Ganglionic(cell body outside CNS) neuron to organ

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Say something about the parasympathetic system

Craniosacral b/c
preganglionic neurons are in the brain stem or sacral levels of spinal cord
ACH at preganglionic and postganglionic synapses

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Mention the outflows of the parasympathetic system and what they control

•Cranial outflow
III- pupils constrict 
VII- tears, nasal mucus, saliva 
IX- parotid salivary gland
X- visceral organs of thorax and abdomen: 
   -Stimulates digestive glands  
   -⬆️motility of smooth muscles of GI
   -⬇️heart rate 
   -Causes bronchial constriction

•Sacral outflow(S2-4)
from pelvic splanchic nerves
supply all pelvic organs and 2nd half of large intestine

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Mention the outflows of the sympathetic system and what they control

Neurons are in lateral horn of grey matter from T1-L2

Preganglionic NT: ACH
Postganglionic: Norepinephrine
Postganglionic (sweat glands): ACH

Vasoconstriction 
Dry mouth
Pupil dilation 
⬆️heart and respiratory rates 
⬆️glucose mobilization

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The adrenal gland belongs to the ______ division of the NS

What function does it subserve❓

Sympathetic

It caused a body-wise release of epinephrine and norepinephrine in an extreme emergency

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A tumor of the adrenal medulla is known as ❓

What are the clinical features❓

Pheochromocytoma

⬆️arterial pressure
⬆️blood flow to muscles
⬆️blood glucose
⬆️mental activity 
⬆️cellular metabolism 
⬆️glycogenolysis

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The amygdala can stimulate sympathetic activity

True or false❓

True

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The enteric nervous system refers to a collection of neurons in the walls of the GI

What does it include❓

Myenteric plexus of Auerbach

Submucous plexus of Meissner

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Tell me a bit about NTs

ACH-Acetyl CoA+Choline by CAT
-neuromuscular jnctn

Dopamine-in VTA and substantia nigra

NE-found in locus coerulus

EPI-sympathoexcitatory
-found in adrenal medulla and medulla oblongata

5HT- found in raphe nuclei in brainstem

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Talk extensively on drug intervention by cholinergic transmission

Precursor transport
🚫
Hemicholinium

Synthesis

Storage
🚫
Vesamicol

Release
🚫
Botulinum toxin

Receptor+action
🚫Atropine (anti M)
🚫Succinylcholine (anti Nm)
🚫Trimethaphan (anti Nn)

✔️Carbachol
✔️Pilocarpine

Degradation
🚫Neostigmine (R)
🚫Organophosphate (NR)

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The fate of ACH degradation could either be in ❓

Nerves:
True
Specific
Highly potent

Or 
Plasma:
False
Nonspecific, binds to any ester
Less potent

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Physiostigmine can be correctly described as❓

An indirect agonist of Ach receptors

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Talk extensively on drug intervention by adrenergic transmission

Tyrosine 
⬇️ 🚫Metyrosine 
DOPA
⬇️🚫Reserpine 
Vesicle 
⬇️
Release 🚫Bretylium 
              🚫Guanethidine

              ✔️Amphetamine
              ✔️Tyramine
              ✔️Ephedrine 
⬇️
Receptor action 🚫Phentolamine
                            🚫Propanolol

                        ✔️Albuterol
                        ✔️Isoproterenol ⬇️ Recapture by uptake  ✔️Cocaine  ✔️Tricyclic antidepressants eg imipramine

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What are the sites where catecholamines are released❓

NE: Sympathetic postsynaptic endings

Adrenal medulla:
E: 80%
NE: 20%

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What is the fate of catecholamines❓

Active reuptake: 80-90%
Destruction: 7%
Excretion: 3%

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How does “pargyline” work❓

Antidepressants like parygline are MAO inhibitors

🚫degradation of catecholamines
⬆️catecholamine levels in CNS

What are the effects of the ANS in the skin❓

Skin: apocrine gland
S: secretion

Skin: eccrine gland
P: no action

What are the effects of the ANS in the special senses❓

Iris of eyes:
S: dilation
P: constriction

Tear gland:
S: inhibition
P: secretion

What are the effects of the ANS in the endocrine system❓

Adrenal cortex
S: secretion

Medulla
P: no action

What are the effects of the ANS in the digestive system❓

Gallbladder
S: relaxation
P: constriction

Intestine
S: decreases peristalsis
P: increases peristalsis

Smooth muscles
S: relaxation
P: constriction

Sphincters
S: constriction
P: relaxation

Pancreas
S: decreases
P: increase

What are the effects of the ANS in the respiratory system❓

S: dilate bronchioles
P: constrict bronchioles

What are the effects of the ANS in the heart❓

S: increases heart rate
P: decreases heart rate

What are the effects of the ANS in the blood vessels of skin and others❓

S: constriction
P: dilation

What are the effects of the ANS in the urinary system❓

Bladder S: relaxation P: constriction Urinary sphincter S: constriction P: relaxation

What are the effects of the ANS in the reproductive system❓

Penis S: erection P: ejaculation Vagina S: erection P: constriction of vagina

Classify PNS receptors

1. Cholinergic R. •Nicotinic: Nm-neuromuscular/muscle type Nn-neuronal/ganglion type •Muscarinic: M1, M3, M5-Gq coupled M2, M4-Gi coupled ``` 2. Adrenergic R. alpha1-a1A, a1B, a1D alpha2-a2A, a2B, a2C b1 b2 b3 ``` 3. Dopamine R. D1, D2, D3, D4, D5

Where are a1 receptors found❓ | What functions do they subserve❓

a1: •Postsynaptic effector cells- esp. smooth muscle * vasoconstriction * hepatic glycogenolysis

Where are b1 receptors found❓ | What functions do they subserve❓

Distribution: •postsynaptic effector cells- •heart, lipocytes, brain, presynaptic adrenergic/cholinergic terminals Functions •⬆️cardiac rate and force •relaxation of GI smooth muscle

Where are b3 receptors found❓ | What functions do they subserve❓

* Postsynaptic effector cells-lipocytes | * lipolysis

Where are b2 receptors found❓ | What functions do they subserve❓

Distribution: •postsynaptic effector cells- •smooth muscle, cardiac muscles ``` Functions: • Bronchodilation •Vasodilation •Relaxation of visceral smooth muscle •Hepatic glycogenolysis ```

Where are a2 receptors found❓ | What functions do they subserve❓

Distribution: •Presynaptic adrenergic nerve terminals (autoreceptor) •Platelets, lipocytes, smooth muscle Functions: •Inhibitor of transmitter release •Platelet aggregation •Relaxation of smooth muscles

Describe the effects of adrenergic and cholinergic receptors on the heart

Rate of contraction- Adrenergic: ⬆️b1 Cholinergic: ⬇️M2 Force of contraction Adrenergic: ⬆️b1 Cholinergic: ⬇️M2

Describe the effects of adrenergic and cholinergic receptors on the 1. Arteries 2. Veins 3. Skeletal muscles

On arteries A: a1 causes vasoconstriction On veins A: a2 causes vasoconstriction On skeletal muscle A: b2 causes vasodilation

Describe the effects of adrenergic and cholinergic receptors on the lungs

A: b2- Bronchiodilation C: M3- bronchioconstriction

Describe the effects of adrenergic and cholinergic receptors on the genitourinary smooth muscle

On bladder wall: b2-Relaxation M3-Contraction On ureter a1-Contraction M3-Relaxation On Sphincter a1-Contraction M3-Relaxation On uterus b2-relaxation a1-contraction Penis/Vas a1- Ejaculation M3- Erection

Describe the effects of adrenergic and cholinergic receptors on the GIT

•Salivary glands: a1- ⬆️secretion M3- ⬇️secretion •Smooth muscles: Walls: a2, b2- relaxation M3- contraction Sphincters: a1- contraction M3- relaxation •Secretion M3- ⬆️ secretion

Describe the effects of adrenergic and cholinergic receptors on the 1. Skin 2. Sweat glands

•Skin: Hair follicles, smooth muscle: a1- contraction, piloerection •Sweat glands: Thermoregulation: M3: ⬆️secretion Apocrine(stress): a1: ⬆️secretion

Describe the effects of adrenergic and cholinergic receptors on the 1. Liver 2. Fat cells 3. Kidney 4. Pancreas

Liver: a1, b2- glycogenolysis and gluconeogenesis Fat cells: b1, b3- lipolysis Kidney: b1- increase renin secretion Pancreas: a2- ⬇️insulin release

Describe the effects of adrenergic and cholinergic receptors on the eye

``` •Iris: Radial muscle: a1- contraction (mydriasis) Circular muscle: M3- contraction (miosis) ``` •Ciliary muscle: b2- relaxation M3- contraction Cholinergic effects: - contraction of pupillary constrictor muscle (miosis-constricted pupil) - contraction of ciliary muscle (bulge of lens) - near vision - ⬆️ outflow of aqueous humor Adrenergic effects: - contraction of pupillary dilator muscle (mydriasis- dilated pupil) - stimulation of ciliary epithelium - ⬆️production of aqueous humor •Ciliary epithelium: b2- ⬆️secretion of aqueous humor

Ach mediated vasodilation works via❓

Muscaranic receptors on the endothelium ⬆️Nitric oxide production from arginine- induces smooth muscle relaxation ⬆️Cyclic GMP ⬆️Protein kinase ⬇️Ca2+ ⬇️Ca2+ sensitivity of cross bridge formation